It can be viewed here: https://github.com/rbtying/Companion-Cube

Download here:

Robot Controller
Source code is released into the public domain, but if you use it, I’d appreciate it if you cite me somewhere (Robert Ying).

You’ll also need to have the appropriate rxtx native library in the same folder as the jar file when running it—you can download that here

Corresponding Arduino Code:

void setup() {
  Serial.begin(115200);
}

// method that sets motor speeds from -255 to 255
// corresponding to full reverse and full forward
void setLeftMotor(int speed);
void setRightMotor(int speed);

byte nextByte() {
  unsigned long start = millis();
  while (millis() - start < 100) {
    if (Serial.available()) {
      return Serial.read();
    }
  }
  return 0x00;
]

void loop() {
  while (Serial.available()) {
    switch(Serial.read()) {
      case 0xC1: setLeftMotor(2 * nextByte()); break;
      case 0xC2: setLeftMotor(-2 * nextByte()); break;
      case 0xC5: setRightMotor(2 * nextByte()); break;
      case 0xC6: setRightMotor(-2 * nextByte()); break;
      default: setLeftMotor(0); setRightMotor(0); break;
    }
  }
}

For the past two weekends I’ve been working on organizing and executing my Eagle project, which is to construct a pair of lecterns for Lynbrook High School. Noticing that we have a shortage of such pieces of furniture, and that they are rather expensive to acquire directly, I decided to build these lecterns to benefit both the faculty and the student population at my school.

I started my project by designing a quick 3D model to lay out the dimensions and get an idea of what it would look like:

And then built it over the course of a weekend with the help of scouts from my troop. This weekend, we put the finishing touches on it by staining and varnishing the wood, so that the color will last longer and the lectern will be sturdier and more durable in general.

A slideshow of the various service project sessions:

Scouts working on measuring and assembling parts of the first lectern

Some scouts marking out lines to be cut

Mr. Ying getting ready to cut some plywood

Scouts beginning to nail plywood to the frame underneath

A scout positioning a part to be glued.

Scouts working together to use the nailgun

A completed lectern! Not quite stained yet, though.

Scouts discussing what to do next

Scouts working outside

Two completed lecterns!

And the rest of the group...

Scouts beginning to stain the lectern

Scouts sanding down the surfaces

Some more staining

Sanding down the ... other ... lectern

Scouts applying varnish to the lecterns

Finishing up the varnish work

Scouts admiring their work

A few more scouts celebrating

A completed and finished project!

More details about the project can be found by reading my project reports, linked below:

• Day 1 Report
• Day 2 Report
• Day 3 and 4 Report

Thanks to all of the people who helped me out on this project!

More than just the debate, though, my speaking seems to have changed pretty significantly—I used to get relatively few speaker points, and rely on argumentation to win, but at Prospect I walked away with the second speaker award (following first by only 0.25 speaker points).

Since Prospect had hidden elimination rounds, the final round (that is, the Finals round) was rather interesting. The second speaker on the team we were supposed to debate (Milpitas GO) had decided to leave with his girlfriend, since we were unaware that it was actually the Finals round. As a result, another member of their team stepped in to fill the spot, and we began the debate. Just after my first speech, however, their coach ran in and forfeited them, giving us the win… with a seven-minute round.

The Companion Cube—with new wheels!

I finished up the wheel replacement today with a pair of Vex Omniwheels, which have little rollers on them to allow movement perpendicular to the way they’re mounted, thus resolving the previous shearing force problems.

An Omniwheel

Unfortunately, since my motor shafts are 6mm single-flat and the Vex wheels are designed for 0.125″ square, I had to drill the wheels out a bit to make it work. Lacking a drill press, I made do with a slightly smaller drill bit, a hand drill, and a rotary tool, adding in a few screws to adjust the fit and to lock the wheel against the single flat. Although there were some mistakes, I think it turned out rather well:

Closeup of the left side of the robot

Closeup of the right side of the robot

The larger wheels get over bumps more easily, and they make it faster, both to turn and to drive—the omniwheels are especially helpful while turning, as they allow me to treat the system as a two-wheel system at the back instead of a four-wheel system like it actually is.

Got some new rear drive wheels, but I'm still waiting on the omniwheels for the front.

I’ve also got a (really short) video from before I started the wheel switch:

A short (and incomplete) list of changes:

1. Switch from old laptop motherboard to an Artigo pico-itx computer
2. Move the Kinect down—empirical data shows that it does not need to be placed very high to get useful readings
3. Elevate the base (by using bigger wheels): I’ve had troubles getting over bumps due to low ground clearance
4. Change microcontrollers from an ATMega328P to a ATMega2560
5. Add an LCD for quick feedback on important things like battery voltage and motor speed

Source code is available for download—there’s a Git repository at tpmo.im/robot.git.

git clone git://tpmo.im/robot.git

Alternatively, browse the repository over the internet here

Pictures:

Replaced the computer and moved the kinect. It's a lot smaller now!

Added a LCD for status feedback

Closeup on the LCD